JP2002043143A - Col part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide coil parts whose cost can be reduce by reduction of man- hours, and which can be miniaturized and thinned. SOLUTION: Print coil patterns 6 are formed on the surface/reverse surfaces of an insulating base material 5 to a thickness of 80 to 300 μm. The coil patterns 6 and 6 at the surface and the reverse are electrically connected on the inner peripheral side through the insulating base material 5 by the through- hole conductor 7, and a coil unit 9 is constituted. Magnetic cores 2 and 3, whose surfaces are insulated, are combined to the coil unit 9. The outer peripheral side terminals 60 and 61 of the coil patterns 6 are connected to electrodes 8a and 8b formed at the end parts on the surface, and the reverse surface of the insulating base material 5 and the coil unit 9 is constituted. In an L-shaped metallic terminal 4, a horizontal part 4a is abutted on or is fixed to the base of the magnetic core 2, and a vertical part 4b is electrically connected to the electrodes 8a, 8b and 8c so as to fix them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coil component such as a thin transformer or a choke coil used for an electronic device or a power supply.

[0002]

2. Description of the Related Art With the recent miniaturization of electronic equipment, there is a demand for miniaturization and thinning of power transformers and choke coils. In order to meet such demands, various transformers and choke coils in which the winding is formed by a printed coil without using a bobbin have been used.

FIG. 10 is an external view of a conventional transformer of this kind.
FIG. 10A shows the layer structure. This coil component is formed by laminating a plurality of insulating base materials having a spiral coil pattern formed on one or both sides thereof via an insulating layer, and forming a through hole 21 at the center of the laminated substrate 20.
0 is sandwiched between the I-type magnetic core 22 and the E-type magnetic core 23, and the middle leg 24 of the E-type core 23 is inserted into the through hole 21 and assembled. An external connection terminal 25 is inserted into a through hole 26 provided in the substrate 20.

[0004]

In the above-mentioned conventional coil component, the through-hole 26 into which the external connection terminal 25 is to be inserted is formed by bonding a copper plate to the upper and lower surfaces of an insulating base material, and forming a through-hole after lamination. A step of performing through-hole plating and patterning the surface copper plate by etching is required, which requires a great deal of man-hours and raises the cost.

Further, in the case of a small coil component, there is a problem that the ratio of the through hole 26 and the land required around the through hole 26 to the volume is large, which is an obstacle to further miniaturization.

Conventionally, the cores 22 and 23 are
0, and the terminals 25 are inserted separately into the through-holes 26 and attached to the board 20. However, since the bottom surfaces of the terminals 25 are securely brought into contact with the attachment board (not shown) and soldered. In addition, the bottom surface of the core 22 must be designed to float about 0.1 mm to 0.2 mm from the bottom surface of the terminal 25. For this reason, there has been a problem that the height of the coil component is increased by the amount by which the bottom surface of the core 22 is raised above the bottom surface of the terminal 25.

[0007] In view of the above problems, an object of the present invention is to provide a coil component capable of reducing costs by reducing man-hours and capable of being reduced in size and thickness.

[0008]

According to a first aspect of the present invention, there is provided a coil component, wherein a printed coil pattern having a thickness of 80 to 300 μm is formed on the front and back surfaces of an insulating base material, and the coil patterns on the front and back surfaces are formed on the inner periphery thereof. A coil part is formed by combining a magnetic core having at least a surface insulated by forming a coil unit by being electrically connected through the insulating base material on the side thereof. The outer peripheral end of the coil pattern formed on the front and back surfaces is connected to electrodes formed on the front and back ends of the insulating base material to form a coil unit, and the L-shaped metal terminals are connected to the horizontal portion. The magnetic core is in contact with or fixed to the bottom surface, and the vertical portion is electrically connected to and fixed to the electrode.

As described above, the outer peripheral terminal of the coil pattern is connected to the electrodes on the front and back ends of the insulating base material, and the metal terminals are connected to the electrodes, so that the conventional external connection terminal is provided. Steps such as through-hole processing for insertion, through-hole plating, and patterning by etching are not required, and cost can be reduced by reducing man-hours. Further, it is not necessary to secure an area for processing a through hole or an area for forming a land, and the area for terminal connection can be significantly reduced, so that the size can be reduced accordingly. In addition, since the metal terminal has an L-shape and has a structure in which the horizontal portion of the metal terminal is brought into contact with the bottom surface of the core, the metal terminal does not protrude outward, and the miniaturization is promoted even in this terminal structure. In addition, the horizontal portion of the metal terminal has a structure in which it abuts or is fixed to the bottom surface of the core, so that the height dimension can be reduced and the thickness can be reduced.

The coil component according to claim 2 has a plurality of coil units according to claim 1, and at least some of the coil units are arranged such that the coil patterns on the front and back surfaces of the insulating base material are on the inner peripheral side. A coil unit is formed by penetrating the insulating base material and electrically connected thereto, and has a structure in which the plurality of coil units are laminated and integrated via an insulating adhesive sheet. At the ends of the front and back surfaces of the insulating base material at the same position in the direction, electrodes having or not connected to the coil pattern are provided, and the electrodes on the front and back surfaces of the insulating base material of each of the coil units are arranged in the stacking direction. By arranging them, an end face electrode portion of the laminated coil unit is formed, and a vertical portion of the metal terminal is electrically connected to and fixed to the end face electrode portion.

[0011] In such a structure in which a plurality of coil units are stacked, the degree of reduction in the number of steps becomes large,
Further cost reduction can be achieved as compared with the case of the first aspect.

According to a third aspect of the present invention, in the coil component according to the first or second aspect, instead of the L-shaped metal terminal, a U-shaped metal terminal is used as the metal terminal, and the upper and lower magnetic cores are sandwiched by the U-shaped metal terminal. It has a structure.

As described above, by forming the metal terminal in a U-shape, a structure in which the metal terminal sandwiches the core can be realized, and the metal terminal can be securely and firmly fixed to the core. Further, it is not always necessary to bond the cores. When the cores are not bonded, the number of steps is reduced.

[0014]

FIG. 1A is a perspective view showing a choke coil (inductor) as an embodiment of a coil component according to the present invention, FIG. 1B is an exploded perspective view thereof, and FIG. )
Is a layer structure diagram of the substrate. 2A is a cross-sectional view of the center of the substrate, FIG. 2B is a cross-sectional view of one end of the substrate, FIG. 2C is a cross-sectional view of the other end of the substrate, (D) is a sectional view of the coil component.

In FIGS. 1A and 1B, reference numeral 1 denotes a substrate having a laminated structure, reference numerals 2 and 3 denote an I-type magnetic core and an E-type magnetic core which are respectively assembled to the substrate 1 from the outside, and 4 denotes a metal terminal. 1 (C) and FIGS. 2 (A) to 2 (D), reference numeral 5 denotes an insulating base made of resin or the like, and reference numeral 6 denotes a spiral coil pattern formed on the front and back surfaces of the insulating base 5, respectively. These coil patterns 6, 6 are connected on the inner peripheral side by conductors 7 provided in through holes of the insulating base material 5. Outer peripheral side terminals 60 of the coil patterns 6, 6 on the front and back surfaces,
Reference numeral 61 is integrally connected to the electrodes 8a and 8b at the front and back ends. Insulating base material 5
A plurality of discontinuous dummy electrodes 8c are provided in the coil pattern for flattening the entire end of the coil unit 9 including the coil unit 6 and the coil unit 6.

Reference numeral 10 denotes an insulating material which is disposed on the front and back surfaces of the insulating base material 5 so as to cover the coil pattern 6 and joined. As the insulating material 10, an adhesive sheet made of, for example, a prepreg made of glass epoxy resin, which can be bonded to the insulating base material 5 by heat and pressure can be used. Thus, by arranging the insulating material 10 on the front and back surfaces of the coil unit 9, the substrate 1 shown in FIG. 1B is configured.

The coil pattern 6 is described in, for example,
As described in No. 1-204361, a base thin film layer and a resist thereon are formed on an insulating base material 5 made of glass epoxy resin, ceramic, or the like, and the resist is removed in the form of a coil pattern having narrow grooves. Using a method of forming a mushroom-shaped coil pattern having a cross-sectional shape larger than the groove width on the groove portion where the groove has been removed and in the vicinity thereof, the distance between the coil patterns 6 in the radial direction is accurately set and narrowed. This is effective in that the current capacity is increased by increasing the cross-sectional area of the coil pattern 6.

The thickness of the insulating substrate 5 is, for example, 60
μm, and the thickness of the coil pattern 6 is 200 μm. In order to make the coil component thin and secure the current capacity, the thickness of the insulating base material 5 is 10 μm to 10 μm.
0 μm, thickness of coil pattern 6 is 80 μm to 300 μm
m is preferable.

The substrate 1 constructed as described above is actually manufactured by multi-cavity as described later. The substrate 1 is provided with through holes 11 in a laminated material and cut into individual chips. . Then, as shown in FIGS. 1A and 2D, the I-type magnetic core 2 and the E-type magnetic core 3 are
The central leg 3a of the E-shaped magnetic core 3 is fitted in the through hole 11 of the E-type magnetic core 3, sandwiching the substrate 1, the horizontal portion 4a of the terminal 4 is brought into contact with the bottom surface of the I-type magnetic core 2, and the vertical portion 4b is arranged in the stacking direction. One electrode 8
a and 8c, or 8c and 8c, or 8b and 8c, which are electrically connected and fixed by solder 12 or welding. The cores 2 and 3 are wound with a tape or fixed to each other with an adhesive.

As described above, the outer terminals 60, 61 of the coil pattern 6 are integrally connected to the electrodes 8a, 8b provided on the front and back ends of the insulating base material 5, and the connection portion of the terminal 4 (terminal With the configuration of the electrodes, it is not necessary to perform a conventional process such as through-hole processing for inserting an external connection terminal, through-hole plating, and patterning by etching, so that cost can be reduced by reducing man-hours. Further, it is not necessary to secure an area for processing a through hole or an area for forming a land, and the area for terminal connection can be significantly reduced, so that the size can be reduced accordingly. The metal terminal 4 has an L shape, and the metal terminal 4
(The structure may be fixed by an adhesive), so that the metal terminals do not protrude outward, and the miniaturization is promoted also in this terminal structure. Further, the horizontal portion 4a of the metal terminal 4 is configured to be in contact with the bottom surface of the core 4, so that the height dimension can be reduced and the thickness can be reduced.

As shown in FIG. 2D, if the contact portion (fixed portion) of the terminal 4 on the bottom surface of the core 2 is formed as a notch 2a, the bottom surface of the terminal 4 and the bottom surface of the core 2 are substantially formed. It can be formed on the same surface, and further thinning can be achieved. In this case, the depth of the cutout portion 2a of the core 2 is set to be smaller than the thickness of the horizontal portion 4a of the terminal 4 so that the horizontal portion 4a of the terminal 4 slightly projects from the bottom surface of the core 2. .

FIG. 3 (A) is a perspective view showing another embodiment of the coil component of the present invention, FIG. 3 (B) is an exploded perspective view thereof,
FIG. 4 is a layer structure diagram of the substrate. The present embodiment is configured as a thin transformer, and includes a coil unit 9A in which a coil pattern 6A connected by a through-hole conductor on the inner peripheral side is formed on the front and back surfaces of an insulating base material 5A, and an insulating base material 5B A coil unit 9B having a coil pattern 6B formed on the front and back surfaces of a coil unit 9C and a coil unit 9C having a coil pattern 6C connected by a through-hole conductor 7 on the inner peripheral side on the front and back surfaces of the insulating base material 5C, respectively. The insulating material 10 is interposed between the units 9A to 9C, and the front and back surfaces of the plurality of coil units 9A to 9C are covered with the insulating material 10 and laminated, and are integrally fixed to form the substrate 1A. . The magnetic cores 2 and 3 are mounted on the substrate 1A.

Also in this embodiment, the outer peripheral terminals 6 of the coil patterns 6A, 6A on the front and back surfaces of the insulating base material 5A are also provided.
2, 63 are the electrodes 8d, 8 at the front and back ends of the insulating base 5A.
e, respectively. Also, the outer peripheral terminals 64, 6 at both ends of the coil pattern 6B on the surface of the insulating base material 5B.
5 are integrally connected to the electrodes 8f and 8g at the ends of the surface of the insulating base material 5B. The outer peripheral terminals at both ends of the coil pattern on the back surface of the insulating base material 5B are also integrally connected to the electrodes 8h and 8i at the end portions on the back surface of the insulating base material 5B. The outer peripheral terminals 66, 67 of the coil patterns 6C, 6C on the front and back surfaces of the insulating base material 5C are connected to the electrodes 8 on the front and back ends of the insulating base material 5C.
j and 8k.

The electrodes 8d to 8d are arranged in the stacking direction.
k, or by arranging these electrodes 8d and dummy electrodes 8c, as shown in FIGS. 3A and 3B, the terminal electrode portions 13a to 13e are formed. Then, the terminal 4 is fixed to these terminal electrode portions 13a to 13e by soldering or welding in the same structure as described above. One of the coil patterns 6A to 6C is used as a primary winding, and the other is used as a secondary winding.

As described above, in the case of a coil component having a large number of laminations, the degree of reduction in the number of man-hours becomes large, and further cost reduction can be achieved as compared with the case of the first aspect.

FIG. 5 is a process chart showing an example of a manufacturing process of a substrate used in the present invention. First, as shown in FIG. 5A, coil patterns 6X and 6Y are formed on the front and back surfaces of the insulating base material 5X by patterning. In this example, an example is shown in which two types of coil patterns 6X and 6Y are formed on only one side, but only one type may be formed. As shown in FIG. 5B, the insulating material 5X in which the coil patterns 6X and 6Y are formed vertically and horizontally or another insulating material in which different coil patterns are formed and the insulating material 10X are alternately stacked. Then, as shown in FIG. 5 (C), these are heat-pressed to produce a substrate material 1X for multi-cavity production.

Next, as shown in FIG. 5D, a through-hole 11 of the substrate 1X is made by NC processing, and thereafter, as shown in FIG.
As shown in (1), the substrate material 1X is cut along the vertical and horizontal cutting lines 15 to 18 into individual substrates.

FIG. 6 is a view showing an example of a process for producing a coil component after producing a substrate as described above. FIG.
As shown in FIG. 6A, a lead frame 14 on which a required number of terminal portions 4X are formed is prepared, and as shown in FIG.
The E-shaped magnetic core 3 is set in the lead frame 14 such that the side legs 3b of the E-shaped magnetic core 3 are orthogonal to the arrangement direction of the terminal portions 4X. Then, as shown in FIG. 6C, the substrate 1B is set on the E-type magnetic core 3 in the lead frame 14. In this case, cream solder is applied to one of the terminal portions 4X or the terminal electrode portions 13a to 13e, and the through hole 11 of the substrate 1B is fitted into the central leg 3a of the E-shaped magnetic core 3, and the side surface of the substrate 1B Terminal electrode portions 13a-1
3g correspond to the terminal portions 4X. Then Figure 6
As shown in (D), the I-type magnetic core 2 is placed and fixed,
In this state, the terminal electrodes 13 to 13e are soldered to the terminal 4X through a reflow furnace. Then, as shown in FIG. 6E, the terminal portion 4X is cut from the frame portion of the lead frame to obtain a product. In this example, the structure in which the E-type magnetic core 3 side is the bottom side is shown.

FIG. 7A is a perspective view showing a choke coil (inductor) as another embodiment of the coil component of the present invention, FIG. 7B is an exploded perspective view thereof, and FIG. 8 is a side view thereof. is there. In the present embodiment, a U-shaped metal terminal 4A is used instead of the L-shaped terminal 4, and the U-shaped metal terminal 4A is used.
Thus, the upper and lower magnetic cores 2 and 3 are sandwiched therebetween. 7 and 8, the same reference numerals as those in FIGS. 1 and 2 denote parts or portions that perform the same function.

As described above, by forming the metal terminal 4A in a U-shape, a structure in which the metal terminal sandwiches the core can be realized, and the fixing of the metal terminal 4A to the cores 2 and 3 becomes reliable and strong. In addition, it is not always necessary to bond the cores 2 and 3 together, which can contribute to a reduction in man-hours.

When this structure is realized, as shown in FIG. 8, a notch 3a is also provided in the contact portion (fixed portion) of the upper core 3 of the metal terminal 4A, so that the structure can be made thin. According to this embodiment, the notch 3a
Is smaller than the thickness of the horizontal portion 4c of the metal terminal 4A, so that both surfaces of the coil component can be used as mounting surfaces on the mounting board.

FIG. 9 shows the use of the U-shaped metal terminal 4A in the coil component (transformer) of the embodiment shown in FIGS. 3 and 4. In this case, too, the same effects as in FIGS. 7 and 8 are obtained. Can be given.

According to the present invention, a through-hole 11 is not provided at the center of the substrate 1 and a magnetic core is arranged at the center of the insulating base 5.
It is also applicable to the structure of 00-183212.

[Brief description of the drawings]

FIG. 1A is a perspective view showing a choke coil (inductor) which is an embodiment of a coil component of the present invention,
(B) is an exploded perspective view, and (C) is a layer structure diagram of the substrate.

2A is a cross-sectional view of a central portion of the substrate of FIG. 1, and FIG.
Is a cross-sectional view of one end of the substrate, (C) is a cross-sectional view of the other end of the substrate, and (D) is a cross-sectional view of the coil component.

FIG. 3A is a perspective view showing another embodiment (transformer) of the coil component of the present invention, and FIG. 3B is an exploded perspective view thereof.

FIG. 4 is a layer structure diagram of the substrate of FIG. 3;

FIG. 5 is a diagram illustrating an example of a manufacturing process of a substrate used for the coil component of the present invention.

FIG. 6 is a diagram illustrating an example of a manufacturing process after manufacturing a coil component substrate according to the present invention.

FIG. 7A is a perspective view showing a choke coil (inductor) as another embodiment of the coil component of the present invention,
(B) is an exploded perspective view thereof.

FIG. 8 is a side view of the coil component of FIG. 7;

FIG. 9A is a perspective view showing another embodiment (transformer) of the coil component of the present invention, and FIG. 9B is an exploded perspective view thereof.

FIG. 10A is a perspective view showing a conventional coil component,
(B) is an exploded perspective view thereof.

[Explanation of symbols]

1, 1A, 1B: substrate, 1X: substrate material, 2: I-type magnetic core, 3: E-type magnetic core, 4, 4A: metal terminal, 4a,
4c: horizontal portion, 4b: vertical portion, 4X: terminal portion, 5, 5A
5C, 5X: insulating base material, 6, 6A-6C, 6X, 6
Y: coil pattern, 7: through-hole conductor, 8a, 8
b, 8d to 8k: electrodes connected to the coil pattern, 8
c: dummy electrode, 9, 9A to 9C: coil unit, 1
0: Insulating material, 11: Through hole, 12: Solder, 13a to 13
g: terminal electrode part, 14: lead frame, 60 to 67:
Outer terminal

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[Procedure amendment]

[Submission date] July 24, 2000 (2007.2
4)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 6

[Correction method] Change

[Correction contents]

FIG. 6

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01F 17/00 H01F 15/10 F (72) Inventor Koji Okada 1-13-1 Nihonbashi, Chuo-ku, Tokyo F-term in TDK Corporation (reference) 5E070 AA01 AA11 AB10 BA08 CB06 CB12 CB18 EA02 EB03

Claims (3)

[Claims] 1. A printed coil pattern having a thickness of 80 to 300 μm is formed on the front and back surfaces of an insulating base material, and the coil patterns on the front and back surfaces penetrate the insulating base material on the inner peripheral side thereof and are electrically connected. A coil component comprising a coil unit which is connected to form a coil unit, and a magnetic core having at least an insulating surface on the coil unit, wherein an outer peripheral side terminal of a coil pattern formed on the front and back surfaces of the insulating base material Are connected to the electrodes formed on the front and back ends of the insulating base material to form a coil unit, and the L-shaped metal terminal is abutted or fixed on its horizontal portion to the bottom surface of the magnetic core, A coil part electrically connected and fixed to the electrode. 2. A method according to claim 1, further comprising a plurality of coil units, wherein at least a part of the coil units is such that the coil patterns on the front and back surfaces of the insulating base material penetrate the insulating base material on the inner peripheral side thereof. And has a structure in which the plurality of coil units are stacked and integrated via an insulating adhesive sheet, and each coil unit is located at the same position in the stacking direction. At the ends of the front and back surfaces of the insulating base material, there are electrodes connected or not connected to the coil pattern, and the electrodes on the front and back surfaces of the insulating base material of each of the coil units are arranged in the laminating direction, thereby forming a laminated coil. A coil component comprising an end face electrode portion of a unit, and a vertical portion of the metal terminal is electrically connected and fixed to the end face electrode portion. 3. The metal terminal according to claim 1, wherein a U-shaped metal terminal is used as the metal terminal instead of the L-shaped metal terminal, and the upper and lower magnetic cores are sandwiched by the U-shaped metal terminal. And coil components.